Viscoelastic Buckling Analysis of Laminated Composite Columns
SourceA linear viscoelastic buckling analysis for laminated composite columns was developed using the quasi-elastic approach. The analysis includes transverse shear deformation (TSD), transverse normal deformation (TND), and bending-extensional coupling. The Rayleigh-Ritz method of solution was employed to solve the governing equation derived from the Theorem of Minimum Potential Energy. Viscoelastic column buckling behavior was investigated for four laminate configurations, [0]24, [0/±45/0]3s, [0/±45/90]3s, [±45]6s, and for column length-to-thickness ratios (ℓ/t) ranging between 35.8 and 150.0. The results for graphite/epoxy show that viscoelastic effects are significant, reducing the critical buckling load by 10% to 20%, depending upon laminate configuration. For geometries where TSD is important (ℓ/t < 50.0), the effects of viscoelasticity are magnified by the matrix-controlled shear stiffness contribution.